Electromagnetic coupling



K. MELLER.

ELECTROMAGNETIC COUPLING. I APPLICATIONJILED JUNE 21, 1921.

1,4344 36. Patented Oct. 31', 1922 Patented Oct. 31, 1922.

UNITED STATES PATENT OFFICE.

KARL MELLER. OF SIEMENSSTADT, NEAR BERLIN, GERMANY, ASSIGNOR TO SIEMENS-SCHUCKERTWERKE GESELLSCHAFT MIT BESCHRANKTER HAFTUNG, OF SIEMENS- STADT,NEAR BERLIN, GERMANY. A CORPORATION OF GERMANY.

ELECTROMAGNETIC COUPLING.

Application filed June 21,

7 '0 all whom it may concern Be it known that I, KARI. MnLLER, a citizenot the German Empire. residing at Siemensstadt, near Berlin, Germany,have invented certain new and useful Improvements in ElectromagneticCouplings (for which I have tiledapplications in Germany December 12th,1919; Austria April 21st, 1920; Great Britain June 5th, 1921; FranceMarch 22nd, 1921, and Belgium March 24th. 1921), of which the followingis a specification.

My invention refers to electromagnetic couplings and its particularobject is to facilitate the changing over of such couplings.

An essential. requirement in the use of electromagnetic couplings, moreespecially those arranged in double for changing over from one directionof rotation to the other. is the possibility of changing over thecoupling as rapidly as ever possible and at the correct moment, without,however, endangering the transmission and coupling-gear.

The drawback, attaching to these couplings, in not changing over thecoupling immediately after the electric switch has been changed over, isdue to remanent magnetism. i. e. a certain time being required, untilthe magnetism in the cut-out portion of the coupling has suflicientlydiminished to allow the magnetic armature to drop, and also, until themagnetism in the cut-in portion of the coupling has suflicientlyincreased to attract the armature. In order to obtain a rapid action ofthe coupling, it is necessary, therefore, to provide that the magnetismdiminishes and increases, respectively, as quickly as possible. This canbe effected by connecting a resistance of high value in parallel andanother one in series with each magnet coil. In this case, however, itis of importance. that the dropping of the armature by one and theattracting by the other half of the coupling take place simulta neously.In order to attain this, the resistances must be adjusted in a certainway with regard to one another as well as to the magnetic conditions ofthe coupling. It is, however, impossible in actual working, on accountof the wear at the friction surfaces of the coupling, to prevent theair-gap between armature and magnet from changing in the course of time.In this manner the magnetic conditions are changed in regard 1921.Serial No. 479,318.

to the increase and decrease of magnetization and the adjustment,previously effected,-

to the most favourable conditions for changing over is disturbed.

This drawback is avoided by designing the series-resistances as alsothose connected in parallel, not only in the form of so-called adjustingresistances, which only permit of an initial adjustment to the mostfavourable conditions, but also in the form of regulating resistances,by means of which it is possible to re-adjust from time to time to thebest conditions for changing over, in case the conditions should havechanged.

Regulating series-resistances have already been used in connection withmagnetic couplings, such resistances however, fulfilling an entirelydifferent purpose, since they are int-ended to vary the output of thecoupling by increasing or decreasing the tractive effort. Thesearrangements are generally of much greater extent than that disclosed inthe present invention, and no regard can of course be given in sucharrangements to the maintenance of the most favourable conditions forchanging over.

In the drawings attached to this specification and forming part thereoftwo couplings embodying my invention are illustrated diagrammatically byway of example. In these drawings- Figure 1 represents a magneticreversible coupling in which each of the two magnets is provided with anindividual shunt resistance and both magnets have a joint seriesresistance; and

Figure 2 renresents such a coupling in which each of the magnets has itsindividual series resistance.

Referring to Fig. 1. a is the coupling. 6 and c are collector-rings forreceiving and returning the magnetization current. 0 is the ad- Iiustable series resistance, which, on being adcreasing; the paralleli'esistunce tlie time required for the diminution of the magnetism isreduced. it is the change-over switch, which is shifted, at the pointsof contact 00,

y, 2, to the left (arrow 71 for the heavy torque to the right (arrow 77"for the light torque. at is the current supply system, n being one, 92the other conductor. With the coupling cut-ii1 for the heavy torque, thepath of current is as follows: The current passes from 72 over fusethrough parts Off series-resistance e to collector-ring 7), magnet coil(6, ring 0, through. the changeover switch u tothe Contact piece y andnow hack into the other conductor 71 In Fig. 2 another modificetion isrepresented, showing; the additional feature that the series resistanceis div ded into two separatesect'ionsw bein a series resistance used forheavy torques and e being a series resistance torjli'g'ht torques,wherebyic is possible to reduce or increase the time required "formagnetization tor both move ments according to the different conditions.

A cut out (Z is inserted into the return line, which permits the circuitto be opened at will.

l he same reference letters are employed to indicate corresponding partsin Figs. 1 and 2.

I claim:

Device for correctly and rapidly changing over electromagneticcouplings, cm L rismg; magnetic coils, regzyulatmg; resistances KARLMrJLLER.

